This question already has an answer here:
The original charger for my laptop model can output 87W. Sometimes I forget it at work and I use my Nintendo Switch Charger (Output: 15V, 2.6A = 39W) for emergencies.
I was wondering if using a charger that may not be able to input the amount of power needed (for example maybe the laptop needs 45W so it will take the rest from the battery) could damage the laptops battery?
Extra: If there is no problem, would that also hold for this power bank: https://www.amazon.com/AUKEY-30000mAh-Portable-Delivery-Nintendo/dp/B071CQYBSN